The series: Seahawks lead 15-14 and have taken the past two by a combined 71-16 score. Each of those games was in Seattle, however. The 49ers won last year in San Francisco, 13-6, and haven’t lost to the Seahawks at home since 2008.

The early line: 49ers by 3.

Key players: Quarterback Colin Kaepernick has had an up-and-down second year as a starter, but has been better the past two weeks now after the return from injury of Mario Manningham and Michael Crabtree. Kaepernick has completed 34 of 52 passes for 510 yards, four touchdowns and no interceptions in wins over the Rams and Redskins. ... Running back Frank Gore, who has had some of the best games of his career against Seattle, is having a solid season with 821 yards. But he has just 121 yards on 41 carries in the past three games.

San Francisco’s keys to success: The 49ers go as Kaepernick goes. He has an 88.9 quarterback rating for the season, but just 46.2 in the team’s four losses, including a season-low 20.1 in Seattle’s 29-3 win over the 49ers on Sept. 15. In that game, the 49ers couldn’t run, with Gore getting just 16 yards on nine carries. Expect the 49ers to try to open it up more this game, though, with Crabtree and Manningham back.